Fix CVE-2017-1000364 by backporting the patches for gen3

Backport of patches from upstream for 4.9
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=cfc0eb403816c5c4f9667d959de5e22789b5421e
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=5d10ad6297260e9b85e7645ee544a6115bb229e4
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=linux-4.9.y&id=ce7fe8595902c3f03ef528c2dc1928b3f4b67fcf

Bug-AGL: SPEC-705

Change-Id: Ic10d65a80f9cd334067e507715dfe9589fbde744
Signed-off-by: Jan-Simon Möller <jsmoeller@linuxfoundation.org>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/9883
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Stéphane Desneux <stephane.desneux@iot.bzh>

1 files changed, 52 insertions, 0 deletions

diff --git a/meta-agl-bsp/meta-rcar-gen3/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch b/meta-agl-bsp/meta-rcar-gen3/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch
new file mode 100644
index 000000000..cb6614964
--- /dev/null
+++ b/meta-agl-bsp/meta-rcar-gen3/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch
@@ -0,0 +1,52 @@
+From 6c98443e18289db3ff9afb68575a607cea468ae0 Mon Sep 17 00:00:00 2001
+From: Hugh Dickins <hughd@google.com>
+Date: Tue, 20 Jun 2017 02:10:44 -0700
+Subject: [PATCH 3/3] mm: fix new crash in unmapped_area_topdown()
+
+commit f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 upstream.
+
+Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of
+mmap testing.  That's the VM_BUG_ON(gap_end < gap_start) at the
+end of unmapped_area_topdown().  Linus points out how MAP_FIXED
+(which does not have to respect our stack guard gap intentions)
+could result in gap_end below gap_start there.  Fix that, and
+the similar case in its alternative, unmapped_area().
+
+Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
+Reported-by: Dave Jones <davej@codemonkey.org.uk>
+Debugged-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Hugh Dickins <hughd@google.com>
+Acked-by: Michal Hocko <mhocko@suse.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/mmap.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/mm/mmap.c b/mm/mmap.c
+index d71a61e..145d3d5 100644
+--- a/mm/mmap.c
++++ b/mm/mmap.c
+@@ -1813,7 +1813,8 @@ unsigned long unmapped_area(struct vm_unmapped_area_info *info)
+ 		/* Check if current node has a suitable gap */
+ 		if (gap_start > high_limit)
+ 			return -ENOMEM;
+-		if (gap_end >= low_limit && gap_end - gap_start >= length)
++		if (gap_end >= low_limit &&
++		    gap_end > gap_start && gap_end - gap_start >= length)
+ 			goto found;
+ 
+ 		/* Visit right subtree if it looks promising */
+@@ -1916,7 +1917,8 @@ unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info)
+ 		gap_end = vm_start_gap(vma);
+ 		if (gap_end < low_limit)
+ 			return -ENOMEM;
+-		if (gap_start <= high_limit && gap_end - gap_start >= length)
++		if (gap_start <= high_limit &&
++		    gap_end > gap_start && gap_end - gap_start >= length)
+ 			goto found;
+ 
+ 		/* Visit left subtree if it looks promising */
+-- 
+2.1.4
+